Including header files

This is a discussion on Including header files within the C Programming forums, part of the General Programming Boards category; I apologize if this is a simple question, but I am having trouble including header files into my main program ...

  1. #1
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    Including header files

    I apologize if this is a simple question, but I am having trouble including header files into my main program body. For example, I will have all of a library's prototypes in the Library.h file and the implementations of those prototypes in the Library.c file (which includes Library.h). Now, when I try to include Library.h into my Main.c the program is unable to find the function implementations in the Library.c, however, if I include Library.c everything seems to work fine. Why is this so, and am I wrong in thinking I should just be able to include the header file am I missing something here?

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    What you have is a linker error - #include-ing Library.h is what the compiler needs so that it knows what functions/global variables exist and what types they have, but they have to be present at link-time (the stage after compilation) if you're to actually use them. Fix: When you compile, specify both Main.c and Library.c on the command-line, like so:

    Code:
    $ cc Main.c Library.c -o Main
    (adjust options for your compiler, obviously)

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    Got it working, thanks for the advice

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